There are a large number of peptide compounds having a cyclic structure (cyclic peptide compounds) in nature, and it is known that they have various physiological activities. For example, Urotensin II and somatostatins are cyclic peptide compounds having a disulfide bond in a ring, and it is known that Urotensin II and somatostatins have, for example, vasoconstriction action and inhibitory action on growth hormone (GH) secretion of hypophysis, respectively.
Cyclic peptide compounds exhibit various types of action in vivo, and interest in novel action and the like has motivated synthesis of cyclic peptide compounds having a novel structure. This has encouraged development of novel processes for the synthesis of cyclic peptide compounds.
It is known that the disulfide bond in the rings of the cyclic peptide compounds such as Urotensin II is relatively unstable in vivo. Thus, substitution of the disulfide bond in the rings of the cyclic peptide compounds with a bond of other forms has been carried out to synthesize cyclic peptide compounds having increased stability in vivo. For example, a disulfide bond of a peptide of formula (15) (SEQ ID NO: 27) isolated as a peptide binding to the SH2 domain of the Grb7 protein is substituted with a thioeter bond to synthesize a compound of formula (16) (SEQ ID NO: 28).

This has also encouraged the development of processes for the synthesis of cyclic peptide compounds.
However, forming a disulfide bridge via cysteine is the only way available in current processes for the translational synthesis of cyclic peptide compounds, and it is difficult to maintain a cyclic form of peptides under reduction conditions or in human blood. This brings a problem that peptides changed into a linear form have significantly low in vivo stability, compared with the original cyclic peptides. Thus, there have been demands for development of novel processes for synthesizing cyclic peptides that maintain in vivo stability.
Further, ribozymes having a wide range of tRNA aminoacylation activities, and aminoacylation of tRNAs using the ribozymes are known.    Patent document 1: JPA 2003-514572    Patent document 2: JPA 2005-528090    Non-patent document 1: H. Murakami, H. Saito, and H. Suga (2003) “A versatile tRNA aminoacylation catalyst based on RNA” Chemistry & Biology, Vol. 10, 655-662    Non-patent document 2: H. Murakami, A. Ohta, H. Ashigai, H. Suga (2006) “The flexizyme system: a highly flexible tRNA aminoacylation tool for the synthesis of nonnatural peptides” Nature Methods 3, 357-359